Broaching tool

ABSTRACT

A broaching tool for correcting the inside diameter (i.d.) of irregular tubing, and arranged to be driven downhole and uphole by a mechanical jar, comprising a mandrel having spaced stops thereon with a plurality of cutting spools reciprocatingly received in a slidable manner upon the mandrel. Each spool has a circumferentially extending cutting blade made into the form of a spiral, and is further provided with radially spaced longitudinally extending elongated slots for maintaining the blade free of cuttings.

United States Patent Moore, Jr. June 11, 1974 BROACHING TOOL l Primary Examiner-Andrew R. .luhasz [76] lnvemor' gag 3 26 BOX 2486 Assistant Examiner-W. R. Briggs Attorney, Agent, or FirmMarcus L. Bates [22] Filed: Feb. 14, 1973 [21] Appl. No.: 332,394 ABSTRACT ussseesm A broaching tool for correcting the inside diameter (i.d.) of irregular tubing, and arranged to be driven downhole and uphole by a mechanical jar, comprising a mandrel having spaced stops thereon with a plurality of cutting spools reciprocatingly received in a slidable manner upon the mandrel. Each spool has a circumferentially extending cutting blade made into the form ofa spiral, and is further provided with radially spaced longitudinally extending elongated slots for maintain- 6 Claims, 6 Drawing Figures n ll .II I

PATENTEDJUNH 1914 v 3.8151193 sum 1 0F 2 PATENTEBJUR 1 1 m4 SHEEIZUF 2 FIG. 5

l BROACHI'NG TOOL BACKGROUND OF THE INVENTION Well bores, such as oil wells and water-wells for example, are generally provided with production tubing which extend thousands of feet downhole to a production formation. It is often desirable to remove cement, burrs, or accumulated deposits of various calcified chemicals from the inside peripheral wall surface of the tubing. At other times, it is desirable to remove burrs and egg-shaped cross-section configurations from the interior of production tubing.

When installing various downhole production equipment in the tubing string, it is desirable that the interior surface thereof be free from irregularities and that the minimum i.d. of the tubing conform to some required value. This is especially so where a free piston type plunger is to be installed in the tubing.

It is therefore desirable to be able to return the id of production tubing to some predetermined minimum value by shaving excess material therefrom so as to prevent plungers from lodging downhole.

SUMMARY OF THE INVENTION This invention relates to a well tool and specifically to a broaching tool in combination with a mechanical jar for correcting the inside diameter of a tubing string by shaving material from selected portions thereof. The invention comprises a mandrel having spaced stop means thereon. One of the stop means is in the form of a fastener placed at the upper end of the mandrel, so as to enable the tool to be affixed to a tool joint which also includes a jar.

A plurality of cylindrical spools are reciprocatingly received upon the mandrel in a slidable manner, with the combined length of the spools being less than the effective distance between the stops, so as to enable the spools to jointly slide along the mandrel and to be received by the stops with a jarring action.

Each spool has a circumferentially extending blade which outwardly extends into engagement with the wall of the tubing. The blades spiral several revolutions outwardly from and about the spool. Radially spaced longitudinally extending slots are formed into the spool and extend to a depth to effectively remove cuttings therefrom.

The cutting edge of at least two of the spools are diametrically opposed to one another, thereby enabling the broaching tool to engage the tubing with a cutting action as the tool is moved in either an uphole or downhole direction. The configuration of the blade causes the tool to remove material from the interior side wall of the tubing string with a shaving action.

Accordingly, a primary object of this invention is the provision of a broaching tool in combination with a jar for correcting tubing i.d.

Another object of the invention is to provide a broaching tool which removes material from the interior wall of a tubing string in a new and improved manner.

A further object of this invention is to provide improvements in broaching tools which enable a series of cutting spools to be run downhole and uphole, thereby removing selected portions of the tubing id. in a steplike manner.

Another object of the invention is the provision of improvements in broaching tools which include a blade design which is self-cleaning and which shaves material from the interior side wall of the tubing string in a new and improved manner.

These and various other objects and advantages of the invention will become readily apparent to those skilled in the art upon reading the following detailed description and claims and by referring to the accompanying drawings.

The above objects are attained in accordance with the present invention by the provision of a combination of elements which are fabricated in a manner substantially as described in the above abstract and summary.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary, part cross-sectional, hypothetical view which discloses a broaching tool made in accordance with the present invention, and with the tool being disposed within a borehole;

FIG. 2 is an enlarged, part cross-sectional view of part of the apparatus disclosed in FIG. 1;

FIG. 3 is an enlarged portion of the apparatus disclosed in FIG. 2;

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 2;

FIG. 5 is a fragmentary, part cross-sectional view of a portion of the apparatus disclosed in the foregoin figures; and

FIG. 6 is a broken, part cross-sectional, disassembled view of part of the apparatus disclosed in FIGS. 1, 2, and 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1 there is illustrated a cased borehole 10 which penetrates formation 1 l, and within which there is disposed tubing 12, sometime called a tubing string. A broaching tool, generally illustrated by the numeral at 14, forms a portion of the tool string 16. The tool string is suspended by a wire line 18 by attachment to a sinker bar by the usual swivel. A mechanical jar 20, which can take on any number of forms, is attached to the sinker bar by sub 21, also sometimes called a tool joint. The jar has the usual piston'rod 22 reciprocatingly received within the illustrated cylinder, and attached to the before mentioned broaching tool by means of a sub 23.

The broaching tool of the present invention includes a plurality of spools disposed thereon for correcting the id of the production tubing, as will be discussed in greater detail later on in this disclosure.

Looking now to the details of FIG. 2, in conjunction with the remaining figures, spools 24, 25, 26 are provided with the illustrated counterbore to enable each spool to be slidably received in close tolerance relationship along the outer peripheral surface of the mandrel so that the spools can jointly or severally reciprocate thereupon. The axial center line of mandrel 27 is longitudinally aligned with the axial center line of each of the concentrically arranged spools. The upper marginal end of the mandrel is threaded, as illustrated at 28, to enable lock nut 29 to be received thereon. The lock nut is provided with spaced flats to enable the nut to be jammed against a sub or the box of a jar. Lower'stop means 30 .is in the form of an enlargement having an outside diameter (o.d.) slightly less than the effective o.d. of the spools, but greater than the o.d. of the mandrel, thereby presenting the illustrated shoulder against which the spool is abuttingly received.

It will be noted that spool 26 is arranged for cutting in an upward direction while the remaining spools are arranged for cutting when driven in a downward direction. The relative position of the three spools may be arranged in any one of the several possibilities, if desired; however, the arrangement of FIG. 2 is preferred.

Looking now in greater detail to the specific details and design of the spool, and in particular to FIGS. 3 5, the spool is seen to have opposed end portions 31, 32 with banks of cutting blades being disposed therebetween in a discontinuous manner. The blades are formed by sloped wall portion 33 which is ground flat at 34 to thereby leave a cutting edge 35. Radially spaced longitudinally extending slots 36 are formed into the outwardly extending blades with the slot extending approximately to the same depth as the blade so as to avoid unduely weakening the structure of the body of the spool, while at the same time providing a maximum longitudinally extending slot for removing debris formed by the cutting blade.

As seen in greater detail in the illustration of FIG. 5, circumferentially extending spiral wall 33 slants inwardly towards the mandrel where it curves at 33' to reverse its direction, and continues to curve outward to form the cutting edge 35. Flat 34 is provided on the blade by grinding a surface which is parallel to the axial longitudinal center line of the mandrel.

Accordingly, as sloped cutting edge 35 engages the inside peripheral wall surface of the tubing, material removed or shaved therefrom will curl into the form of a pigtail 39.

Moreover, in grinding the spools, the o.d. is varied from 31 to 32 so that the effective diameter of the spool at 31 is 0.005 inches less-than the o.d. at 32, thereby providing a slight taper so that each of the spiraling blades must contact and cut away a minute portion of the interior surface of the tubing.

In the preferred embodiment of the invention, the pitch of a two inch o.d. spool is two inches, although a pitch of 1% inches and 1% inches have also proven satisfactory. In the two inch o.d. tool, two inches of lost motion is provided between the upper stop means 29 and the uppermost spool 26. The cutting edge of the blade preferably is made of tungsten carbide, which is ground. to a sharp point by placing the spool in a lathe and surfacing the spool with a high speed water cooled tool grinder. This expedient enables the taper to be easily and inexpensivelyincorporated into the spool.

In operation, the broaching tool is attached to the box of a sub by threadedly engaging the upper end therewith, and utilizing lock nut 29 as a jam nut, thereby preventing inadvertent loss of the tool. The sub 23 is attached to a conventional jar and the entire apparatus incorporated into a wire line tool joint by including a sinker bar therewith in the illustrated manner of FIG. I.

The tool joint is run downhole at a speed of about 5 feet per second until the obstructions within the tubing wall arrest downward motion, whereupon the jar is then utilized to force the downward travel of the tool. Upon reaching the bottom of the borehole, the tool is returned to the surface. Should an obstruction be encountered while traveling uphole, the upwardly directed cutting blades on spool 26 will remove any debris which might prevent the orderly travel of the tool.

It is preferred to utilize three sizes of spools which differ in o.d. by .1 inches. The smallest o.d. spools are first run into the tubing string, followed by the second and then the last or largest set of spools. This expedient enables the irregular tubing i.d. to be enlarged or broached in a step-wise or successive manner, which prevents injury to either the tubing or to the cutting blade of the tool.

1. A broaching tool for correcting the inside diameter of tubing, comprising a longitudinally extending mandrel having opposed end portions, means forming spaced stops in the form of an enlargement at one end thereof and a fastener means at the remaining end thereof, so that the tool can be affixed to a jar by said fastener means;

a plurality of spools, means by which said spools are slidably received in a reciprocatingmanner upon said mandrel, the combined length of said spools being less than the distance measured between said stops so as to enable said spools to jointly slide along said mandrel between said stops;

each spool having a circumferentially extending outwardly directed cutting blade, said blade being spirally arranged about and forming the outermost surface of said spool, with each spiral extending about each spool for several revolutions; means forming longitudinally extending slots radially spaced from one another and formed into the outermost marginal edge portion of the spool and extending to a depth substantially equal to the depth of the cutting blade; the cutting blade of one of said spools being disposed in an upward direction while the cutting blade of another of said spools is disposed in a downward direction to thereby enable the tool to remove material from the interior of the tubing while traveling either uphole or downhole therein; so that the mandrel can be attached to a jar and the tool forced through the well tubing, thereby removl 4. The tool of claim 1 wherein the cutting blade of the spool diverges in an outward direction and terminates in a land formed in the outermost marginal edge portion thereof, the innermost portion of said blade being curved back upon itself and terminates in an adjacent said cutting edge.

5. The tool of claim 4 wherein said lands are disposed substantially parallel to the longitudinal central axis of said mandrel.

6. The tool of claim 5 wherein said tool is tapered in the direction of the cutting edges to thereby provide 0 the blade of the tool with increasing diameter along the longitudinal length thereof. 

1. A broaching tool for correcting the inside diameter of tubing, comprising a longitudinally extending mandrel having opposed end portions, means forming spaced stops in the form of an enlargemEnt at one end thereof and a fastener means at the remaining end thereof, so that the tool can be affixed to a jar by said fastener means; a plurality of spools, means by which said spools are slidably received in a reciprocating manner upon said mandrel, the combined length of said spools being less than the distance measured between said stops so as to enable said spools to jointly slide along said mandrel between said stops; each spool having a circumferentially extending outwardly directed cutting blade, said blade being spirally arranged about and forming the outermost surface of said spool, with each spiral extending about each spool for several revolutions; means forming longitudinally extending slots radially spaced from one another and formed into the outermost marginal edge portion of the spool and extending to a depth substantially equal to the depth of the cutting blade; the cutting blade of one of said spools being disposed in an upward direction while the cutting blade of another of said spools is disposed in a downward direction to thereby enable the tool to remove material from the interior of the tubing while traveling either uphole or downhole therein; so that the mandrel can be attached to a jar and the tool forced through the well tubing, thereby removing selected portions of the inside diameter of the tubing.
 2. The tool of claim 1 wherein said jar is attached to a wire line and the tool is disposed below said jar to thereby enable the tool to be driven through the tubing.
 3. The tool of claim 1 wherein said stops are provided with a longitudinally extending slot formed into the outermost marginal edge portion thereof to thereby enable debris formed by the cutting blade to be removed therefrom.
 4. The tool of claim 1 wherein the cutting blade of the spool diverges in an outward direction and terminates in a land formed in the outermost marginal edge portion thereof, the innermost portion of said blade being curved back upon itself and terminates in an adjacent said cutting edge.
 5. The tool of claim 4 wherein said lands are disposed substantially parallel to the longitudinal central axis of said mandrel.
 6. The tool of claim 5 wherein said tool is tapered in the direction of the cutting edges to thereby provide the blade of the tool with increasing diameter along the longitudinal length thereof. 